package com.gorkr.hot100.simple;


/**
 * @author 张心宇 <zhangxinyu20@kuaishou.com>
 * Created on 2022-12-21
 */
class TreeNode {
      int val;
      TreeNode left;
      TreeNode right;
      TreeNode() {}
      TreeNode(int val) { this.val = val; }
      TreeNode(int val, TreeNode left, TreeNode right) {
          this.val = val;
          this.left = left;
          this.right = right;
      }
}
public class E617 {
    public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
        return traverse(root1, root2);

    }

    private TreeNode traverse(TreeNode root1, TreeNode root2){
        if(root1==null){
            return root2;
        }
        if (root2==null){
            return root1;
        }
        root1.val += root2.val;
        root1.left = traverse(root1.left, root2.left );
        root1.right = traverse(root1.right, root2.right);
        return root1;
    }
}
